In a manufacturing process of a semiconductor device, various liquid processes such as a wet etching process, a cleaning process and a coating film forming process are performed by supplying processing liquids onto a substrate such as a semiconductor wafer. For example, when performing the liquid process on the substrate by supplying the processing liquid while rotating the substrate and when performing a shake-off drying process on the substrate after the processing liquid is supplied, frictional charging may occur in a surface of the substrate due to a friction between the surface of the substrate and the liquid remaining on the surface of the substrate or due to a friction between the surface of the substrate and an ambient atmosphere. If a surface potential of the substrate is increased as a result of the charging of the substrate, electrostatic breakdown of a device formed on the substrate may occur.
To suppress the electrostatic breakdown of the device while performing a rinsing process, there is proposed a method of using a rinse liquid which is prepared by dissolving carbon dioxide or ammonia in pure water and thus has conductivity. The acidic or alkaline rinse liquid, however, may inflict damage on a film which forms the device. Further, in this method, the electric charging caused by the friction between the surface of the substrate and the ambient atmosphere when performing the shake-off drying process cannot be suppressed sufficiently.
Further, there is also known a method in which a substrate holding member of a spin chuck is formed of a conductive member, and electric charges, which are generated in the surface of the substrate due to the friction, are released through the conductive member (see, for example, Patent Document 1). In this method, however, a sufficient charge removal effect may not be obtained when the entire surface of the substrate is covered with an insulating (dielectric) material.
Patent Document 1: Japanese Patent Laid-open Publication No. 2003-092343